Square Kilometre Array Observatory (Immunities and Privileges) Order 2020

Lord Rees of Ludlow Excerpts

Monday 14th September 2020 Grand Committee

[Lord Rees of Ludlow (CB) [V]]

My Lords, the Minister’s statement should surely be welcomed and uncontroversial. I have no specific involvement to declare, but as Astronomer Royal I am probably one of the few Members of this House familiar with the SKA. I will therefore supplement what the Minister said by outlining for a few minutes the project’s international significance, why the UK’s central role is especially welcome and why this decision has broader long-term benefits extending beyond the science itself.

Astronomy is the grandest environmental science. We are trying to discover the whole “zoo” of objects the cosmos contains—galaxies, stars, planets, black holes, et cetera. Just as Darwin showed how we and our biosphere evolved from the first life on the young earth about 4 billion years ago, we are trying to go back further and trace how the solar system and all the atoms in it emerged from some mysterious beginning nearly 14 billion years ago.

We can also learn new basic physics by observing phenomena where nature has, as it were, created conditions and done experiments we could never simulate in the lab. Within a decade, incidentally, we can observe planets around other stars to check whether they might harbour life. This subject has become a “big science” advanced by international consortia—indeed, in optical astronomy the European Southern Observatory, to which we in the UK belong, has a world lead. It has the biggest and best optical telescope currently and the one now being built will also be a world-beater.

Moreover, other kinds of radiation, not just optical but radio waves, reveal just as much as visible light. Indeed, much of the gas in the universe is hydrogen and radiates only in the radio band. Ever since the 1950s, the UK has been an international leader in radio astronomy, not least because radio waves are not stopped by clouds and rain.

However, there is a fundamental constraint. To get a sharp image of the radio sky would require a dish far bigger than those at Jodrell Bank and elsewhere—literally miles across—which is obviously out of the question. But there is another way to get sharp images. The radiation gathered from an array of separate dishes can be combined to create a map of the radio sky as sharp as a single radio dish the size of the earth.

The SKA exploits this amazing technique, which incidentally was first developed by Martin Ryle in Cambridge in the 1960s. It will comprise hundreds of dishes, with a total surface area of a square kilometre—hence its name—but these dishes will be spread over a large geographical region. Perhaps the biggest challenge, to which the Minister alluded, is the huge computer power needed to combine and process the data flow from all the dishes in the array.

Such an array cannot be built in Britain. It needs large, open and sparsely populated areas. After years of international discussion, two optimal sites were found in the southern hemisphere which have scientific and geopolitical advantages. Half the array will be concentrated in remote pastoral areas of Western Australia, though some outlying dishes in that array will spread right across the continent.

The other half will be in South Africa, centred in a region of the Northern Cape known as the Karoo. Nearly 200 dishes will be concentrated in a region 100 miles across, but some outliers will spread further away into eight other African countries: Ghana, Zambia, Madagascar, Botswana, Namibia, Kenya, Mauritius and Mozambique. South Africa is already a major player in astronomy, having prioritised it for decades. To quote the relevant South African Minister:

“We are determined to ensure the success of what will be the first ever large global research infrastructure hosted in Africa”.


Participation in the SKA project has significantly strengthened South Africa’s data science capabilities, enabling it to close the gap with developed economies.

So much for the background. The SKA hardware is concentrated in two southern countries, but 15 or more nations are contributing, so it needs a governance structure established through international treaties similar to those governing two other sciences that require costly international facilities and multinational partnerships: CERN, the particle accelerator in Geneva, and the European Space Agency. I should add that the SKA is about 10 times cheaper than CERN.

The global headquarters will be the legal entity responsible for constructing and operating the telescopes in the southern hemisphere. The convention was signed, as the Minister said, in 2019 by Australia, China, Italy, the Netherlands, Portugal, South Africa and the UK. Other member nations plan to join and contribute financially and via their expertise.

It is fitting that the world’s future largest radio telescope, the SKA, will have its headquarters at Jodrell Bank—a site recently granted UNESCO world heritage status to mark its pioneering contributions to radio astronomy and the iconic telescope, now called the Lovell Telescope, which was once the world’s largest single dish in radio astronomy. Lovell’s great telescope, incidentally, was commissioned in the 1950s. It has had several updates and is now more than 60 years old, but it is still probing cosmic objects whose very existence was unknown when it was built and, by looking at pairs of neutron stars, conducting some of the most precise tests of fundamental physics and Einstein’s theory of gravity.

Likewise, there is every hope that the SKA will, via periodic upgrades which will deploy computational power beyond today’s conceptual horizon, spearhead cosmic exploration throughout much of the 21st century. It is a benign project that will have a special role in stimulating IT and data-handling in Africa and in the other member countries. It will benefit all participating states, and their number is likely to grow. It is therefore especially welcome for the UK to have a pivotal role, which will be a technological boost to us in this country as well as a boost to our international collaboration. We should surely welcome this decision today.